Hybrid catalyst with monoclinic MoTe2 and platinum for efficient hydrogen evolution

Abstract

Transition metal dichalcogenides (TMDs) are considered as promising catalysts for the hydrogen evolution reaction (HER) owing to their abundant active sites such as atomic vacancies and step edges. Moreover, TMDs have polymorphism, which has stimulated extensive studies on tuning of surface electronic structures for an active HER. The polymorphism in TMDs provides an opportunity for new hybrid catalysts with TMDs and other catalytic metals via surface engineering that can create a novel functional surface of the catalytic electrode for the active HER. Here, we report a hybrid catalyst with monoclinic MoTe2 and platinum (Pt) for the HER. Pt atoms were chemically bound to the surface of monoclinic MoTe2 that has an atomically distorted lattice structure, which produces a distinct Pt-Te alloy layer. The Pt/MoTe2 hybrid catalyst exhibits an active HER with a Tafel slope of 22 mV per decade and an exchange current density of 1.0 mA/cm2, which are the best values among those reported for TMD-based catalysts. The use of minimum amount of Pt on atomically distorted metallic TMDs realizes rich catalytic active sites on large basal planes for efficient hydrogen production.

Direct Vapor Deposition Growth of 1T′ MoTe2 on Carbon Cloth for Electrocatalytic Hydrogen Evolution

“…In contrast to F-1T′/2H MoTe 2 /CC, F-1T′ MoTe 2 /CC exhibits the better HER performance with a −230.7 mV overpotential for a 10 mA/cm 2 current density. This overpotential reveals that F-1T′ MoTe 2 /CC exhibits better HER performance than most of its original samples and other recently reported materials in Table . ,,− Although 1T′ MoTe 2 /Pt and TiP 2 S 6 @MoTe 2 show better her properties, 1T′ MoTe 2 /Pt may accelerate the loss of precious metal Pt, and the preparation process of TiP 2 S 6 @MoTe 2 is too complex …”

“…This overpotential reveals that F-1T′ MoTe 2 /CC exhibits better HER performance than most of its original samples and other recently reported materials in Table 1. 5,14,20−24 Although 1T′ MoTe 2 /Pt and TiP 2 S 6 @MoTe 2 show better her properties, 1T′ MoTe 2 /Pt may accelerate the loss of precious metal Pt, 24 and the preparation process of TiP 2 S 6 @MoTe 2 is too complex. 23 As the electronic configuration of the catalysts actually drives the electrocatalytic reaction process, 6,7 it was believed that the differences in the HER performance between F-1T′/2H MoTe 2 /CC and F-1T′ MoTe 2 /CC mainly originated from the distinction between the electronic properties of 1T′ and 2H MoTe 2 .…”

“…As shown in Table 1, the asprepared F-1T′ MoTe 2 /CC is as stable as MoSe 2 /CC, 21 which shows better HER stability than 1T′ MoTe 2 /glassy carbon, 1T′ MoTe 2 /Pt, 1T′ MoTe 2 /PyC/SiO 2 /Si, and MoSe 2 /glassy carbon. 5,20,22,24 This may be because the 3D network structure of F-1T′ MoTe 2 /CC is conducive to the emission of hydrogen bubbles. In addition, the direct growth of MoTe 2 nanostructures on CC as electrodes not only ensures good electrical contact between catalysts and the current collector but also prevents F-1T′ MoTe 2 from falling off CC.…”

Parameter optimisation for electrochemically activated MoTe2

“…This is in stark contrast to results achieved in prior reports, which show no structural degradation to take place. 7,10 Thus, the degradation is attributed to the application of excessively reductive potentials. In light of these measurements, the optimum parameters were deemed to be 100 cycles in the potential range of +0.2 V and À0.5 V (vs. NHE).…”

“…[1][2][3][4][5] Most noticeably, the ability to electrochemically enhance their activity towards the hydrogen evolution reaction (HER) in operando has sparked a renewed interest. [6][7][8] This 'electrochemical activation' could open up opportunities for the design of more efficient electrocatalysts with their performance being driven by physical stimuli rather than composition. However, in most cases, such electrochemical activation is due to irreversible structural, compositional and/or morphology changes.…”